Traveling along the streets and alleyways of inner-city American neighborhoods, I find commercial signs, graffiti, folk altars and murals that announce why the residents remember their dead, who is worthy of admiration, whom they pray to and the proud achievements of their ancestors. These artifacts, painted or assembled by neighborhood people, represent a shared history of beliefs. They give us glimpses into what the residents of America’s poor minority communities hold as meaningful.

Drawing from this urban graphic art since the 1970s, I have created a photo archive of work devoted to Martin Luther King Jr. that I encountered in New York, Los Angeles, Chicago, Detroit and other cities. I did not set out to form a collection. Instead, I found an image and photographed it and then found another, eventually accumulating a unique, well-defined group of images. These portraits appear on the walls of liquor stores, barber shops, neighborhood markets and fast-food restaurants. Often the business owners gave the artists a free hand with the commissions. (I excluded less spontaneous representations of King in public schools, hospitals and community organizations that were made under the scrutiny of a principal or public official.) Repeatedly revisiting neighborhoods to photograph them, I looked for signs and images that endure, their survival providing the best testimony of their acceptance.

Bridgeport, 2010.

Harlem, New York, 2009. Artist: Estos.

In talking with artists and storekeepers, I learned the various ways these folk images function. They serve many purposes, from helping to sell merchandise, to making businesses more secure against vandalism and crime, to encouraging a sense of pride in poor communities. For example, after the 1992 riots in South Central Los Angeles, many Latino shopkeepers painted King’s portrait on the facades of their businesses to deter rioters. Later, when Latinos became the majority, King’s image was often replaced by that of Christ, the Virgin of Guadalupe and other symbols of Mexican or Central American identity.

On the streets, King is represented in many ways—as a statesman, visionary, hero or martyr. Often his most famous pronouncement, “I have a dream,” accompanies his image. Some paintings depict him as proud and thoughtful, resting head on hand; in others he looks friendly and compassionate, arms outstretched.

Los Angeles, 2006. Artist: Cornell McKennon.

Detroit, 2012.

Los Angeles, 2010.

The sign painters and amateur artists who create these portraits use iconic photographs of King to model their subject. However, they often fall short of producing a good likeness. It is not uncommon for him to turn out looking Latino, Native American or Asian. In Los Angeles in 2013, I had to stop at El Taco Mexicano to ask the cook if the portrait of someone looking like a brown-skinned campesino, depicted between images of Cesar Chavez and JFK, was really of MLK. In black neighborhoods, though, portraits of King rarely include Latino figures. Rather, he is often accompanied by such icons as Malcolm X, embodying righteous anger, or by other black leaders like Nelson Mandela, Harriet Tubman and Rosa Parks. And while King continues to be a popular icon, portraits of Malcolm and Mandela are fading out, with few new ones replacing them. In group portraits, King takes center stage, usually as the largest figure. Since 2009, he has been painted with President Obama. A local resident explained the pairing by saying, “Rosa Parks sat so Martin Luther King could walk. Martin Luther King walked so Obama could run. Obama ran so we all can fly.”

In Latino neighborhoods, figures such as Pancho Villa, Benito Juárez and Cesar Chavez appear in company with King. And on one occasion, among the ruins of what was once Detroit’s Chinatown, I found a mural in which he appears with Asian features; the caption demanded justice for Vincent Chin, a Chinese-American autoworker who was murdered in a racially motivated attack. On a viaduct on Chicago’s South Side, I discovered a mural by William Walker depicting King as a crucified saint. Walker, a trained African-American artist influenced by the Mexican muralist tradition, envisioned him as round-faced and with pronounced Mexican-Indian features.

It is ironic that, given King’s lifelong struggle against segregation and poverty, his name and likeness have become one of the defining visual elements of the American ghetto, a place he worked his whole life to abolish. His dream of justice and equality for all seems as distant for the seemingly permanent ghettos of today as it was when he was alive.

Los Angeles, 2004.

Chicago, 1980. Artist: B. Walker.

Harlem, New York, 2008.

I value these street images of King in all their earnest misrepresentations because of the hopes they embody. But most murals and street portraits are ephemeral. Paint fades, businesses change hands, art is defaced and neighborhood demographics shift. If folk art museums collect murals at all, they typically are commissioned works by professional artists. Such museums seldom collect photographs. My pictures are often the only lasting record of these public works of art. As I find and photograph them during my urban explorations, I take satisfaction in creating a permanent record of historically important subject matter that is often overlooked and, as the urban fabric changes, will inevitably disappear.

I’ve created an online MLK project available on Flickr. I encourage people to download the images and create their own tributes to King for the fiftieth anniversary of the March on Washington. The images can be used to illustrate stories, as backdrops for dance performances and in videos.

With the collaboration of dozens of friends, I am presenting an MLK poster show (prepared by the State Department for overseas locations) in venues across the United States. They include homeless shelters in Los Angeles; the Brockton, Massachusetts, Historical Society; the Baltimore City Hall; Book Culture, an independent bookstore in New York City; the Elgin Diner in Camden, New Jersey, a landmark slated for demolition; and the Bagley Grille in downtown Detroit. I am moved by the people who have given their time and money to this guerrilla project. It may be ephemeral, but it has already touched many, and I hope it will touch many more.

Los Angeles, 1993. Artist: Debbie Husband.

Chicago, 1991. Artist: The son of shopowner Mr. Toy.

Highland Park, Michigan, 2009.

Gary Younge writes that, fifty years after the March on Washington, Dr. King’s most famous speech, like his own political legacy, is widely misunderstood.